Photos that appeared in the U.K.'s Daily Mail showed actors Catherine Zeta-Jones and Michael Douglas vacationing in Europe aboard a yacht, and in one, Zeta-Jones holds a cigarette while Douglas walks alongside her.
The photo has kicked up its share of controversy about whether such close proximity to a smoker is risky for the 66-year-old actor, who recently underwent treatment for late-stage throat cancer. A number of medical experts have weighed in on the impact Zeta-Jones' smoking could have on her husband's health.
"There are no specific data that say that cancer survivors exposed to secondhand smoke have a higher risk of cancer coming back, but when I see cancer survivors, I tell them to stay away from both active smoking and secondhand smoking," said Dr. Zoukaa Sargi, assistant professor of clinical otolaryngology at the University of Miami's Miller School of Medicine.
"But we do know that secondhand smoke is very harmful, and assume that if it's bad for the general population, it's bad for cancer survivors, especially if they had a cancer caused by smoking," Sargi added.
While data on secondhand smoke are lacking, experts say active smoking is very risky.
"Those who continue to smoke after successful treatment for throat cancer have a higher likelihood of having a recurrence," said Dr. David Goldenberg, a professor of surgery and oncology at Pennslvania State University's Milton S. Hershey Medical Center.
"If their partner is a smoker, I ask that they do not do it in the home or the car," said Dr. Marshall Strome, director of the New York Head and Neck Institute.
It's not known whether Douglas has quit smoking, but living with a smoker would make it difficult to give up the habit.
"It is exceptionally difficult to quit while living with a spouse who continues to smoke," said Dr. H. Steven Sims, director of the Chicago Institute for Voice Care at the University of Illinois Medical Center. "Psychologically, this is not a situation we would like to create."
"[T]empting a former addicted smoker by smoking around them significantly increases the risk of relapse back into smoking within a year," said Dr. Graham Warren of the Roswell Park Cancer Institute in Buffalo, N.Y.
Dr. Amy Chen, an associate professor in the department of otolaryngology at Emory University in Atlanta, said Zeta-Jones should not be smoking because she is putting her own health at risk in addition to her husband's.
Zeta-Jones has said she wants to quit smoking.
"She can be irritating the healing mucosal surfaces of her husband's mouth, nose, and throat," she said. "In addition, her husband may be tempted to participate also, thus increasing his risk for recurrence and/or a second primary cancer."
But despite the potential risks, other experts say the support of loved one can help him as he continues to recover.
"Common sense dictates that a patient recovering from treatment of head and neck cancer is best off spending time with a loving spouse, even if she has bad habits," said Dr. Gregory Weinstein, professor of otorhinolaryngology at the University of Pennsylvania in Philadelphia.
Zeta-Jones' publicist has not responded to requests for comment.